1. Field of the Invention
This invention relates to a pressure sensor which translates a hydraulic pressure into an electrical signal, and more particularly, to a pressure sensor of the type including a movable body which is subject to a hydraulic pressure and in which a displacement produced in the movable body is converted into an electrical signal.
2. Description of the Prior Art
A conventional arrangement is known in which a diaphragm is subject to a hydraulic pressure and is normally urged by a coiled spring to oppose the hydraulic pressure, with the diaphragm being connected to a slider on a potentiometer. In this arrangement, the potentiometer provides an analog voltage corresponding to the amount of movement of the diaphragm when the latter is subjected to a hydraulic pressure. With this pressure sensor, it is desirable that a thin film resistor forming the potentiometer exhibits a high abrasion resistance and provides a stabilized reading of an output voltage for a given slider position. It is also desired that the movable body and the slider be mechanically connected together with a minimal degree of rattling and that a stabilized contact be maintained between the slider and the thin film resistor in the presence of oscillations or shocks. However, because the slider is brought into contact with the thin film resistor under pressure, an abrasion or oscillations may cause production of an unstabilized output voltage in respect to a hydraulic pressure.